Coupling for washing machine and washing machine having the same

ABSTRACT

Disclosed is a washing machine including a tub; a dehydration basket provided in the tub; a pulsator provided in the dehydration basket; a dehydration shaft to transmit rotary force to the dehydration basket; a wash shaft to transmit rotary force to the pulsator; a driving motor to generate driving force to be transmitted to the dehydration shaft and the wash shaft; and a power conversion device to transmit the driving force of the driving motor simultaneously or selectively to the dehydration shaft and the wash shaft, the power conversion device including a clutch device, and a coupling configured to be pressed in one direction by the clutch device to transmit the driving force of the driving motor to the wash shaft and the dehydration shaft simultaneously and pressed in the other direction by the clutch device to transmit the driving force of the driving motor to the dehydration shaft only.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 2009-0002923, filed on Jan. 14, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field

Embodiments of the present invention relate to a washing machine, which selectively performs a washing operation and a dehydrating operation.

2. Description of the Related Art

In general, a washing machine includes a main body forming an external appearance of the washing machine, a tub provided in the main body to contain washing water, a dehydration basket rotatably provided in the tub, a pulsator rotatably provided in the dehydration basket, a dehydration shaft having a hollow structure and provided in the dehydration basket, a wash shaft provided in the hollow of the dehydration shaft, a driving motor provided on the bottom of the tub to generate driving force, and a power conversion device to transmit the driving force of the driving motor simultaneously or selectively to the dehydration basket and the pulsator.

The power conversion device includes a coupling to selectively transmit the driving force of the driving motor to the dehydration shaft, and a clutch device to raise and lower the coupling.

In the conventional washing machine having the above configuration, when the clutch device is turned on, the coupling is raised and thus the driving force of the driving motor is transmitted to the pulsator, and when the clutch device is turned off, the coupling is lowered and thus the driving force of the driving motor is transmitted simultaneously to the dehydration basket and the pulsator.

However, when the clutch device is turned off in order to convert the washing operation into the dehydrating operation after the washing operation has been completed, the coupling is restricted under the raised state and thus is not lowered. In this case, the coupling and a counterpart connected therewith may be damaged.

SUMMARY

Therefore, one aspect of the embodiment is to provide a washing machine having a structure in which a coupling smoothly moves when a clutch device is operated.

Another aspect of the embodiment is to provide a washing machine, which forcibly releases a restricted state of a coupling when a washing operation is converted into a dehydrating operation.

Additional aspects and/or advantages will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.

The foregoing and/or other aspects are achieved by providing a washing machine including a tub; a dehydration basket provided in the tub; a pulsator provided in the dehydration basket; a dehydration shaft to transmit rotary force to the dehydration basket; a wash shaft to transmit rotary force to the pulsator; a driving motor to generate driving force to be transmitted to the dehydration shaft and the wash shaft; and a power conversion device to transmit the driving force of the driving motor simultaneously or selectively to the dehydration shaft and the wash shaft, the power conversion device including a clutch device, and a coupling configured to be pressed in one direction by the clutch device to transmit the driving force of the driving motor to the wash shaft and the dehydration shaft simultaneously and pressed in the other direction by the clutch device to transmit the driving force of the driving motor to the dehydration shaft only.

The clutch device may include an actuator, and a clutch unit rotated by the actuator.

The coupling may be raised and lowered in connection with the rotation of the clutch unit.

The coupling may include a first flange part and a second flange part separated from the first flange part, the clutch unit being selectively movable in a first direction to press the first flange part and a second direction to press the second flange part.

Terminals of the clutch unit may be disposed between the first flange part and the second flange part.

The foregoing and/or other aspects are achieved by providing a washing machine including a driving motor; and a power conversion device to convert power of the driving motor to selectively perform a washing operation and a dehydrating operation, the power conversion device including a coupling reciprocating between a first position to cause the washing operation to be performed and a second position to cause the dehydrating operation to be performed, an actuator, and a clutch unit moving by a driving force of the actuator and selectively pressing the coupling to move the coupling from the first position to the second position.

The clutch unit may be rotatably connected to the actuator; and the coupling may be raised and lowered to the first and second positions in connection with the rotation of the clutch unit.

The coupling may include a first flange part and a second flange part, the first flange part receiving the moving force of the clutch unit to move the coupling to the first position, the second flange part receiving the moving force of the clutch unit to move the coupling to the second position.

One side of the clutch unit may be disposed between the first flange part and the second flange part.

The foregoing and/or other aspects are achieved by providing a washing machine including a driving motor; and a power conversion device to convert power of the driving motor to selectively perform a washing operation and a dehydrating operation, the power conversion device including an actuator, a clutch unit moving by a driving force of the actuator, and a coupling reciprocating between a first position to cause the washing operation to be performed and a second position to cause the dehydrating operation to be performed, the coupling including a first flange part and a second flange part, the first flange part receiving the moving force of the clutch unit to move the coupling to the first position, the second flange part receiving the moving force of the clutch unit to move the coupling to the second position.

The foregoing and/or other aspects are achieved by providing a coupling for a washing machine, which reciprocates between a first position to perform a washing operation by the movement of a clutch unit and a second position to perform a dehydrating operation by the movement of the clutch unit, the coupling including a first flange part receiving the moving force of the clutch unit in a first direction to move the coupling to the first position; and a second flange part receiving the moving force of the clutch unit in a second direction to move the coupling to the second position.

The first flange unit and the second flange unit may be separated from each other by a designated distance, and each protrude from an outer surface of the coupling in the radial direction.

A reception part to receive terminals of the clutch unit may be formed between the first flange unit and the second flange unit.

The foregoing and/or other aspects are achieved by providing a power conversion device of a washing machine including a wash shaft communicating with a pulsator and a dehydration shaft communicating with a dehydration basket, the power conversion device including: a coupling reciprocating between a first position to cause a washing operation of the washing machine to be performed and a second position to cause a dehydrating operation of the washing machine to be performed; an actuator; and a clutch unit moving by a driving force of the actuator and selectively pressing the coupling to move the coupling from the first position to the second position.

The coupling may transmit a driving force of a driving motor only to the wash shaft in the first position and may transmit the driving force of the driving motor simultaneously to the wash shaft and the dehydration shaft simultaneously in the second position.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:

FIG. 1 is a longitudinal-sectional view illustrating a schematic configuration of a washing machine in accordance with one embodiment;

FIG. 2 is a longitudinal-sectional view illustrating a schematic configuration of a driving unit of the washing machine in accordance with the embodiment;

FIG. 3 is an exploded perspective view of the driving unit in accordance with the embodiment;

FIG. 4 is an exploded perspective view of an essential portion of a power conversion device in accordance with the embodiment;

FIG. 5 is a view illustrating the operation of the driving unit in a washing operation in the washing machine in accordance with the embodiment; and

FIG. 6 is a view illustrating the operation of the driving unit in a dehydrating operation in the washing machine in accordance with the embodiment.

DETAILED DESCRIPTION OF EMBODIMENT

Reference will now be made in detail to the embodiment, an example of which is illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

FIG. 1 is a longitudinal-sectional view illustrating a schematic configuration of a washing machine in accordance with one embodiment, and FIG. 2 is a longitudinal-sectional view illustrating a schematic configuration of a driving unit of the washing machine in accordance with the embodiment.

The washing machine in accordance with this embodiment, as shown in FIG. 1, includes a main body 10 forming the external appearance of the washing machine, a tub 20 installed in the main body 10 to contain washing water, a dehydration basket 30 rotatably provided in the tub 20, a pulsator 40 rotatably provided on the bottom of the dehydration basket 30, and a driving unit 50 to rotate the pulsator 40 or simultaneously rotate the dehydration basket 30 and the pulsator 40.

The main body 10 includes a laundry opening 11 formed through the upper surface of the main body 10 such that the laundry is put into the main body 10 through the laundry opening 11, and a cover 12 rotatably installed on the main body 10 to open and close the laundry opening 11.

The tub 20 has a cylindrical shape, the upper surface of which is opened, and is hung on the main body 10 by a plurality of suspension devices 13 connected to the outer surface of the lower portion of the tub 20. The suspension devices 13 damp vibration generated from the main body 10 or the tub 20 in a washing or dehydrating operation.

The dehydration basket 30 has a cylindrical shape, the upper surface of which is opened, and is provided with a plurality of dehydration holes 31 formed through the circumferential surface thereof such that the inner space of the dehydration basket 30 communicates with the inner space of the tub 20. A dehydration shaft 32 having a hollow structure is extended from the lower portion of the dehydration basket 30 toward the driving unit 50 to transmit the driving force of the driving unit 50 to the dehydration basket 30.

The pulsator 40 is rotated in a regular direction or the reverse direction and thus generates a water current, and the laundry in the dehydration basket 30 is agitated by the water current. A wash shaft 41, which passes through the hollow of the dehydration shaft 32 and is extended toward the driving unit 50 to transmit the driving force of the driving unit 50 to the pulsator 40, is provided on the lower portion of the pulsator 40.

The driving unit 50, as shown in FIG. 2, includes a driving motor 51 to generate driving force from received power, and a power conversion device 100 to transmit the driving force generated from the driving motor 51 simultaneously or selectively to the pulsator 40 and the dehydration tub 30.

The driving motor 51 is a BLDC motor, the rotational speed of which is variously controllable, and includes a stator 51 a and a rotor 51 b rotated by the electromagnetic interaction with the stator 51 a.

The rotor 51 b is provided with a hub 52, which is shaft-coupled with the wash shaft 41, at the center of rotation of the rotor 51 b. One end of the wash shaft 41 is shaft-coupled with the hub 52. Further, the hub 52 includes a teeth part 53 for power transmission, which is engaged with a second teeth part 142 (see FIG. 4) of a coupling 140, which will be described later, (with reference to FIG. 3), and thereby the rotary force of the rotor 51 b is transmitted to the coupling 140.

Hereinafter, with reference to the accompanying drawings, the power conversion device in accordance with this embodiment will be described in detail. FIG. 3 is an exploded perspective view of the driving unit in accordance with the embodiment, and FIG. 4 is an exploded perspective view of an essential portion of the power conversion device in accordance with the embodiment.

As shown in FIGS. 3 and 4, the power conversion device 100 includes an actuator 110 to generate driving force to convert power, a rod unit 120 rectilinearly moving according to the operation of the actuator 110, a clutch unit 130 connected to the rod unit 120 and rotated according to the operation of the rod unit 120, and the coupling 140, which is raised and lowered according to the operation of the clutch unit 130 and transmits the driving force of the driving motor 51 selectively to the dehydration shaft 32.

A lower housing 21 is fixed to the lower portion of the tub 20, and an anti-rotation member 150 is fixed to the lower housing 21.

The anti-rotation member 150 includes an anti-rotation teeth part 151 engaged with a first teeth part 141 of the coupling 140, which will be described later, and a shaft fixing part 152 to rotatably mount the clutch unit 130 on the anti-rotation member 150.

Although the actuator 110 in this embodiment is an electric motor generating rotary force, the actuator 110 is not limited thereto but may be a hydraulic cylinder, a linear motor, a solenoid device, etc.

The rod unit 120 includes a rod 121 provided with one end connected to the actuator 110 by a wire 111 and the other end connected to the clutch unit 130, and a guide case 122 installed in the lower housing 21 to guide the forward and backward movement of the rod 121.

When power is applied to the actuator 110, the wire 111 connected to the actuator 110 is wound, and thus the rod 121 is guided by the guide case 122 and is slid toward the actuator 110.

Therefore, the rod 121 moves forward and backward by the driving force generated from the actuator 110, and rotates the clutch unit 130 connected to the rod 121.

The clutch unit 130, as shown in FIG. 4, includes a first clutch part 131 provided with one side connected to the rod 121, a second clutch part 132 provided with one side rotatably connected to the first clutch part 131 and the other side supporting the coupling 140, and a torsion spring 133 to damp the rotary force of the first clutch part 131 in one direction and transmit the damped rotary force to the second clutch part 132.

A rotary shaft 134 is provided at the connection portion between the first and second clutch parts 131 and 132, and is mounted on the shaft fixing part 152 of the anti-rotation member 150 to rotatably connect the clutch unit 130 to the anti-rotation member 150.

The torsion spring 133 is wound on the rotary shaft 134. One end of the torsion spring 133 is supported by the rear surface of the first clutch part 131 and the other end of the torsion spring 133 is supported by the lower surface of the second clutch part 132. The torsion spring 133 provides elastic force in a direction in which an angle formed by the first and second clutch parts 131 and 132 narrows.

Here, the clutch unit 130 further includes a stopper 135 to restrict the rotation of the second clutch part 132 toward the first clutch part 131 by the torsion spring 133. Although the stopper 135 in this embodiment is formed integrally with the first clutch part 131, the stopper 135 may be formed integrally with the second clutch part 132, or may be formed separately from the clutch unit 130 and be mounted on the clutch unit 130.

The clutch unit 130 further includes an elastic member 136 of a tension spring type provided with one end connected to the first clutch part 131 and the other end connected to the anti-rotation member 150. When the power applied to the actuator 110 is interrupted, the elastic member 136 provides elastic force to rotate the first clutch part 131, having rotated toward the actuator 110, in the direction B and thus to return the first clutch part 131 to its original position. Further, the elastic member 136 causes the end of the first clutch part 131 to be adhered closely to the rod 121, and thus immediately transmits the driving force of the actuator 110 to the first clutch part 131 when the actuator 110 is driven.

Therefore, when the actuator 110 of the power conversion device is driven, if the first clutch part 131 moves in the direction A by the rod 121, the second clutch part 132 connected to the first clutch part 131 moves in the direction C, and thus raises the coupling 140. Here, since the driving force generated to raise the coupling 140 is damped by the torsion spring 133 and is transmitted to the coupling 140, the breakage of parts of the washing machine or the overload of the actuator 110 generated in a process of adhering the coupling 140 closely to the anti-rotation member 150 is prevented, and the power conversion operation is stably achieved.

The coupling 140 in this embodiment is pressed upward by the clutch unit 130 and transmits the driving force of the driving motor 51 to the wash shaft 41 and the dehydration shaft 32, and is pressed downward by the clutch unit 130 and transmits the driving force of the driving motor 51 to the dehydration shaft 32 only.

The coupling 140, as shown in FIGS. 3 and 4, includes the first teeth part 141 provided on the upper portion of the coupling 140 and selectively engaged with the anti-rotation teeth part 151 of the anti-rotation member 150, the second teeth part 142 selectively engaged with the teeth part 53 for power transmission provided on the rotor 51 b of the driving motor 51, and a serration part 143 formed on the inner surface of the coupling 140 to be engaged with a serration part 33 formed on the outer surface of the dehydration shaft 32.

The coupling 140 slides up and down between the anti-rotation member 150 and the rotor 51 b of the driving motor 51. Here, the engagement state between the serration part 143 formed on the inner surface of the coupling 140 and the serration part 33 formed on the outer surface of the dehydration shaft 32 is maintained.

A first flange part 144 protruding in the radial direction and a second flange part 145 separated downward from the first flange part 144 by a designated distance and protruding in the radial direction are provided on the outer surface of the coupling 140 to receive the moving force of the clutch unit 130. The first flange part 144 may form the rear surface of the first teeth part 141.

A reception part 146 is formed by the outer surface of the coupling 140, the first flange part 144, and the second flange part 145, and terminals of the second clutch part 132 are received in the reception part 146.

The second flange part 145 may be formed integrally with the outer surface of the coupling 140, or be formed separately from the coupling 140 and then connected to the outer surface of the coupling 140.

Although this embodiment illustrates that the second flange part 145 protrudes from the outer surface of the coupling 140 in a ring shape, the second flange part 145 is not limited to the above shape, but may be formed on the coupling 140 in any shape that presses the coupling 140 when the second clutch part 132 is lowered.

A coil spring 160 to provide elastic force pressing the coupling 140 downward is provided between the coupling 140 and the dehydration shaft 32.

Through the above configuration, when the actuator 110 is operated, the rod 121 is slid toward the actuator 110, the first clutch part 131 connected to the rod 121 is rotated in the direction A, and the second clutch part 132 is rotated in the direction C in connection with the rotation of the first clutch part 131.

When the second clutch part 132 is rotated in the direction C, the terminals of the second clutch part 132 press the first flange part 144 of the coupling 140 in the raising direction, and thus raise the coupling 140.

When the coupling 140 is raised due to the moving force of the second clutch part 132 and is adhered closely to the anti-rotation member 150, the first teeth part 141 of the coupling 140 is engaged with the anti-rotation teeth part 151 of the anti-rotation member 150. In this state, the driving force of the driving motor 51 is transmitted only to the wash shaft 41 shaft-coupled with the hub 52 of the rotor 51 b of the driving motor 51 and is not transmitted to the dehydration shaft 32, and thus rotation of the dehydration shaft 32 is restricted by the anti-rotation member 150 and the washing operation is performed (with reference to FIG. 5).

When the driving of the actuator 110 has been completed, the elastic member 136 presses the first clutch part 131, the first clutch part 131 is rotated in the direction B, and the second clutch part 132 is rotated in the direction D in connection with the rotation of the first clutch part 131.

Simultaneously, the coil spring 160 is elastically returned to its original position, and presses the coupling 140 downward. However, the coupling 140 may not be lowered due to the engagement between the first teeth part 141 of the coupling 140 and the anti-rotation teeth part 151 of the anti-rotation member 150.

In order to prevent the above problem, in this embodiment, the second flange part 145 is provided on the coupling 140, and when the second clutch part 132 is rotated in the direction D, the terminals of the second clutch part 132 press the second flange part 145 of the coupling 140 in the lowering direction, and thus lower the coupling 140.

When the coupling 140 is lowered due to the moving force of the second clutch part 132 and is adhered closely to the rotor 51 b of the driving motor 51, the second teeth part 142 of the coupling 140 is engaged with the teeth part 53 for power transmission provided on the hub 52 of the rotor 51 b (with reference to FIG. 6). In this state, the driving force of the driving motor 51 is transmitted simultaneously to the wash shaft 41 and the dehydration shaft 32, and thus the dehydrating operation is performed.

Hereinafter, the operation of the washing machine in accordance with this embodiment will be described.

FIG. 5 is a view illustrating the operation of the driving unit in the washing operation in the washing machine in accordance with the embodiment, and FIG. 6 is a view illustrating the operation of the driving unit in the dehydrating operation in the washing machine in accordance with the embodiment.

First, the operation of the driving unit to perform the washing operation will be described.

When power is applied to the actuator 110, the rod 121 is slid toward the actuator 110 by the wire 111, and thereby the first clutch part 131 is rotated in the direction A, as shown in FIG. 5. The rotary force of the first clutch part 131 is transmitted to the second clutch part 132 under the condition that the rotary force is damped by the torsion spring 133, and thus the second clutch part 132 is rotated in the direction C.

When the second clutch part 132 presses the first flange part 144 of the coupling 140 due to the rotation of the second clutch part 132, the coupling 140 is raised against the elastic force of the coil spring 160 and is located at a first position that is adhered closely to the anti-rotation member 150, and the first teeth part 141 of the coupling 140 is engaged with the anti-rotation teeth part 151 of the anti-rotation member 150.

In this state, when power is applied to the stator 51 a of the driving motor 51, the wash shaft 41 shaft-coupled with the rotor 51 b is rotated, but the dehydration shaft 32 serration-coupled with the coupling 140 is not rotated, and thus the washing operation is performed.

Next, the operation of the driving unit to perform the dehydrating operation will be described.

When the power applied to the actuator 110 is interrupted under the condition that the coupling 140 is engaged with the anti-rotation member 150, the rod 121 and the first clutch part 131 are rotated in the direction B by the elastic member 136 and returned to their original positions, and the second clutch part 132 connected to the first clutch part 131 is rotated in the direction D.

When the second clutch part 132 presses the second flange part 145 of the coupling 140 due to the rotation of the second clutch part 132, the coupling 140 is lowered due to the pressure of the second clutch part 132 and is located at a second position that is adhered closely to the rotor 51 b of the driving motor 51, and the second teeth part 142 of the coupling 140 is engaged with the teeth part 53 for power transmission of the rotor 51 b, as shown in FIG. 6.

In this state, when power is applied to the driving motor 51, the driving force of the driving motor 51 is transmitted to the wash shaft 41 and the dehydration shaft 32, and thus the dehydrating operation, in which the pulsator 40 and the dehydration basket 30 are rotated simultaneously, is performed.

Therefore, in this embodiment, when the coupling moves downward to perform the dehydrating operation, the second clutch part forcibly lowers the coupling even though the coupling is firmly connected to the anti-rotation member, thus preventing the breakage of the teeth part of the coupling and the teeth part of the anti-rotation member connected to the coupling.

Although embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

1. A washing machine, comprising: a tub; a dehydration basket provided in the tub; a pulsator provided in the dehydration basket; a dehydration shaft to transmit rotary force to the dehydration basket; a wash shaft to transmit rotary force to the pulsator; a driving motor to generate driving force to be transmitted to the dehydration shaft and the wash shaft; and a power conversion device transmitting the driving force of the driving motor simultaneously or selectively to the dehydration shaft and the wash shaft, the power conversion device including a clutch device, and a coupling configured to be pressed in one direction by the clutch device to transmit the driving force of the driving motor to the wash shaft and the dehydration shaft simultaneously and pressed in the other direction by the clutch device to transmit the driving force of the driving motor to the dehydration shaft only.
 2. The washing machine according to claim 1, wherein the clutch device includes an actuator and a clutch unit rotated by the actuator.
 3. The washing machine according to claim 2, wherein the coupling is raised and lowered in connection with the rotation of the clutch unit.
 4. The washing machine according to claim 1, wherein the coupling includes a first flange part and a second flange part separated from the first flange part, the clutch unit being selectively movable in a first direction to press the first flange part and a second direction to press the second flange part.
 5. The washing machine according to claim 4, wherein terminals of the clutch unit are disposed between the first flange part and the second flange part.
 6. A washing machine, comprising: a driving motor; and a power conversion device to convert power of the driving motor to selectively perform a washing operation and a dehydrating operation, the power conversion device including a coupling reciprocating between a first position to cause the washing operation to be performed and a second position to cause the dehydrating operation to be performed, an actuator, and a clutch unit moving by a driving force of the actuator and selectively pressing the coupling to move the coupling from the first position to the second position.
 7. The washing machine according to claim 6, wherein: the clutch unit is rotatably connected to the actuator; and the coupling is raised and lowered to the first and second positions in connection with the rotation of the clutch unit.
 8. The washing machine according to claim 6, wherein the coupling includes a first flange part and a second flange part, the first flange part receiving the moving force of the clutch unit to move the coupling to the first position, the second flange part receiving the moving force of the clutch unit to move the coupling to the second position.
 9. The washing machine according to claim 8, wherein one side of the clutch unit is disposed between the first flange part and the second flange part.
 10. A washing machine, comprising: a driving motor; and a power conversion device to convert power of the driving motor to selectively perform a washing operation and a dehydrating operation, the power conversion device including an actuator, a clutch unit moving by a driving force of the actuator, and a coupling reciprocating between a first position to cause the washing operation to be performed and a second position to cause the dehydrating operation to be performed, the coupling including a first flange part and a second flange part, the first flange part receiving the moving force of the clutch unit to move the coupling to the first position, the second flange part receiving the moving force of the clutch unit to move the coupling to the second position.
 11. A coupling for a washing machine, which reciprocates between a first position to perform a washing operation by movement of a clutch unit and a second position to perform a dehydrating operation by the movement of the clutch unit, the coupling comprising: a first flange part receiving the moving force of the clutch unit in a first direction to move the coupling to the first position; and a second flange part receiving the moving force of the clutch unit in a second direction to move the coupling to the second position.
 12. The coupling according to claim 11, wherein the first flange unit and the second flange unit are separated from each other by a designated distance, and each protrude from an outer surface of the coupling in the radial direction.
 13. The coupling according to claim 11, wherein a reception part to receive terminals of the clutch unit is formed between the first flange unit and the second flange unit.
 14. A power conversion device of a washing machine including a wash shaft communicating with a pulsator and a dehydration shaft communicating with a dehydration basket, the power conversion device comprising: a coupling reciprocating between a first position to cause a washing operation of the washing machine to be performed and a second position to cause a dehydrating operation of the washing machine to be performed; an actuator; and a clutch unit moving by a driving force of the actuator and selectively pressing the coupling to move the coupling from the first position to the second position.
 15. The power conversion device according to claim 14, wherein the coupling transmits a driving force of a driving motor only to the wash shaft in the first position and transmits the driving force of the driving motor simultaneously to the wash shaft and the dehydration shaft simultaneously in the second position. 